Check out the thread I started about the P4 Thermal Solution a little further down. After delving into Intel's technical datasheet, I found that the maximum allowable for the Northwood CPUs are actually pretty high. Under full load, a 2.53 GHz CPU can take a temperature of 71 degrees Celsius without any loss of reliability. At 2.4 GHz, the CPU can withstand a temperature up to 70 degrees Celsius. So according to Intel, as long as you don't exceed those temperatures, your CPU will run just as expected. (So as the wattage output by the CPU goes up as you overclock, the maximum temperature that the CPU can tolerate will also go up.) So the Northwoods are able to withstand higher temperatures than was previously thought. (Also, the Northwood datasheet makes no mention at all of the 1.6 and 1.8 GHz Northwood CPUs, so those CPUs must then be downrated 2.0 Northwood chips. That explains the great overclocks we're seeing, because Intel planned all of their Northwoods to be at least 2.0 GHz.) So while it can't hurt to cool down your CPU a bit, don't worry too much about it. (Just make sure to keep your voltage below 1.75 volts. In the data sheet, it says that 1.75 volts is the maximum voltage that the CPU can withstand before it starts to lose it's reliability. So you want to make sure you keep the Vcore below that point and try not to max it out to the 1.75 actual volts.)